You know all the reasons this is a bad idea, BoCo, so I'm going to assume you're the grown-up that I know you are, and that you'll use this thing responsibly.
Code:
<script language="JavaScript"
type="text/JavaScript">
if(navigator.appName == "WebTV")
{
window.location = "WebTVHome.html"
}
if(navigator.appName == "Netscape")
{
window.location = "NetscapeHome.html"
}
if(navigator.appName == "Microsoft Internet Explorer")
{
window.location = "ExplorerHome.html"
}
window.location == "Other.html"
</script>
Basically you're making if statements that test the value of navigator.appName, and set window.location depending on what it finds. Not too tough. The window.location breaks processing on the script, so that dangling assignment at the end works as an "else" clause.
Note, I didn't write this, I saved myself some time by googling for it. I can't vouch that it'll work anywhere at any time for anybody on any browser or platform.